The invention relates to multiple-compartment electric motors.
A three-compartment electric motor includes a tubular main frame supporting a stator. A lead end frame and an opposite end frame are supported within the main frame on opposite sides of the stator and divide the interior of the main frame into a motor compartment containing the stator, a first auxiliary or equipment compartment outside of the lead end frame, and a second auxiliary compartment outside of the opposite end frame. The equipment compartment contains electrical control elements for operating the motor. A cap is mounted on the end of the main frame and closes the equipment compartment. The second auxiliary compartment contains other components, such as a fan for a pump to which the motor is attached. Each of the end frames supports a bearing, and the motor also includes a rotor unit including a rotor shaft rotatably supported by the bearings. U.S. Pat. No. 5,006,743, which is assigned to the assignee hereof, discloses such a three-compartment electric motor.
A two-compartment motor is substantially identical to a three-compartment motor except that the two-compartment motor does not include the second auxiliary compartment. Instead, the opposite end frame is located adjacent the end of the main frame.
Prior art multiple-compartment motors are assembled by combining four main assemblies, along with the above-described electrical elements, at final assembly. The four main assemblies are the rotor assembly, the main frame and stator assembly, the lead end frame assembly, and the opposite end frame assembly. During final assembly the electrical control elements are installed in the equipment compartment before the motor is closed.